feat: add task queue with human-in-the-loop approval + work orders + UI bug fixes

Task Queue system:
- New /tasks page with three-column layout (Pending/Active/Completed)
- Full CRUD API at /api/tasks with approve/veto/modify/pause/cancel/retry
- SQLite persistence in task_queue table
- WebSocket live updates via ws_manager
- Create task modal with agent assignment and priority
- Auto-approve rules for low-risk tasks
- HTMX polling for real-time column updates
- HOME TASK buttons now link to task queue with agent pre-selected
- MARKET HIRE buttons link to task queue with agent pre-selected

Work Order system:
- External submission API for agents/users (POST /work-orders/submit)
- Risk scoring and configurable auto-execution thresholds
- Dashboard at /work-orders/queue with approve/reject/execute flow
- Integration with swarm task system for execution

UI & Dashboard bug fixes:
- EVENTS: add startup event so page is never empty
- LEDGER: fix empty filter params in URL
- MISSION CONTROL: LLM backend and model now read from /health
- MISSION CONTROL: agent count fallback to /swarm/agents
- SWARM: HTMX fallback loads initial data if WebSocket is slow
- MEMORY: add edit/delete buttons for personal facts
- UPGRADES: add empty state guidance with links
- BRIEFING: add regenerate button and POST /briefing/regenerate endpoint

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/dashboard/templates/upgrade_queue.html

@@ -59,9 +59,13 @@
       {% endfor %}
     </div>
     {% else %}
-    <div class="mc-empty-state">
+    <div class="mc-empty-state" style="padding:2rem; text-align:center;">
       <p>No pending upgrades.</p>
-      <p class="mc-text-secondary">Proposed modifications will appear here for review.</p>
+      <p class="mc-text-secondary" style="margin-bottom:1rem;">Upgrades are proposed by the self-modification system when Timmy identifies improvements. You can also trigger them via work orders or the task queue.</p>
+      <div style="display:flex; gap:0.75rem; justify-content:center; flex-wrap:wrap;">
+        <a href="/work-orders/queue" class="mc-btn mc-btn-secondary" style="text-decoration:none;">View Work Orders</a>
+        <a href="/tasks" class="mc-btn mc-btn-secondary" style="text-decoration:none;">View Task Queue</a>
+      </div>
     </div>
     {% endif %}
   </div>